Carbohydrate-gluconate products

ABSTRACT

COVERS CARBOHYDRATE-GLUCONATE PRODUCTS AND FOOD COMPOSITIONS THEREOF FORMED BY SELECTIVELY OXIDIZING THE GLUCOSE IN STARCH HYDROLYZATES OR GREENS TO FORM CARBOHYDRATE-GLUCONIC ACID AND CARBOHYDRATE-GLUCONATE MIXTURES. ALSO COVERS MODE OF FORMATION OF THESE COMPOSITIONS.

United States Patent Oflice 3,625,701 Patented Dec. 7, 1971CARBOHYDRATE-GLUCONATE PRODUCTS Raoul Guillaume Philippe Walon,Brussels, Belgium, assignor to CPC International Inc.

No Drawing. Filed Mar. 26, 1969, Ser. No. 810,783

Int. Cl. A23k 1/14 US. Cl. 99-2 2 Claims ABSTRACT OF THE DISCLOSURECovers carbohydrate-gluconate products and food compositions thereofformed by selectively oxidizing the glucose in starch hydrolyzates orgreens to form carbohydrate-gluconic acid and carbohydrate-gluconatemixtures. Also covers mode of formation of these compositions.

There has been an ever-continuing demand for new and inexpensive foodproducts for both human and animal consumption. Improved and economicalmeans for producing food products can go for towards solving thiscountrys and the worlds malnutrition problems. New and improved foodproducts for human consumption can add needed variety to the human diet.

Starch is processed to provide a number of edible foods, one of themajor of which is dextrose which is obtained by crystallization fromstarch hydrolyzates. The dextrose obtained in this manner is then usedas a sweetening agent in many edible products. It would be economicallydesirable to use the starch hydrolyzate liquors per se, rather than tocrystallize dextrose from them, since this would provide economies byavoiding the step of crystallizing out the dextrose. Economical fooduses for greens, which are the starch hydrolyzate liquors remainingafter at least one crop of dextrose has been crystallized out, wouldalso be desirable.

When the term starch hydrolyzates is used hereafter what is meant is anyglucose containing solution produced from a starch. For example, glucosecrystallization liquors, greens, corn syrups, and the like.

The transportation and storage of starch hydroylzates is relativelyexpensive since they generally are not spray dryable, due to their highglucose content, and must be handled in the liquid state. This expensehas to some extent limited the direct use of these materials in foods.It would be a distinct advantage if simple and economical treatment ofstarch hydrolyzates could lead to spray dryable products without theabove-mentioned drawback. It would also be advantageous if the productscontained high calcium or iron contents since calcium is a dieteticnecessity for the formation of bones, teeth, shells, milk etc., inanimals and iron is a dietetic necessary for the prevention of anemia.

It therefore becomes an object of this invention to provide a method oftreating starch hydrolyzates, greens, and similar materials so that theycan more directly be utilized in either animal feeds or human food.

Another object of the invention is to provide specific food products forboth animal and human consumption.

Still another object of the invention is to provide a novelcarbohydrate-gluconate product which can be spray dried for ease inhandling, shipping, etc.

In accordance with the invention, I have discovered a process forprepring novel carbohydrate-gluconate products which comprisesselectively oxidizing the glucose in a starch hydrolyzate solution toform a carbohydrategluconic acid product. A carbohydrate-gluconateproduct may be obtained by addition to the starch hydrolyzate solutionof an amount of base stiochiometrically calculated. to give the desiredamount of metal gluconate in the final" product through neutralizationof the gluconic acid produced.

The base may be added before, during or after the oxidative step. Thecarbohydrate-gluconate product can be converted to acarbohydrate-gluconic acid product by conversion of the metal gluconateinto gluconic acid.

The oxidation may be carried out enzymatically, by electrolysis, or byother chemical methods well known to the art. It is essential that themethod of oxidation be chosen so that glucose is selectively oxidized togluconate, without the concurrent oxidation of other saccharides.

Since the basic process involved here is a conversion of dextrose(glucose) to gluconate, a concomitant reduction in dextrose contentoccurs. In the starch art, it is customary to describe a change in thedextrose content of a material in terms of changes in the total reducingsugar content or dextrose equivalent of the material. The dextroseequivalent (DB) of a saccharide or mixture of saccharities and othermaterials is determined by titrating a solution of a weighed quantity ofsaid saccharide or mixture with a mild oxidizer (Fehlings solution) inthe presence of an oxidizable indicator such as ferrous cyanide until anend point is reached. From the amount of oxidizer used, it is possibleto calculate the weight of pure dextrose with which said amount ofoxidizer would react. This amount of dextrose is referred to as weightof reducing sugars in the sample expressed as dextrose. The dextroseequivalent is then defined as in the following equation:

Dextrose equivalent= 100 weight of reducing sugars as dextrose Weight ofdry substance DETAILED DESCRIPTION OF THE INVENTION In the preferredprocedure, the glucose in starch bydrolyzates is selectively oxidizedenzymatically to a controlled extent by adding quantities of basicsubstances to hydrolyzate-enzyme mixtures and incubating the solutions.Potentially edible products are thereby obtained.

The amount of base added controls the degree of reaction in theenzymatic procedure because once this base has been used up inneutralizing any gluconic acid formed, the pH of the solution begins todrop and the enzyme is inactivated. This generally occrs at a pH ofbelow about 4.5. The glucose oxidase enzyme will not operate to convertglucose to gluconic acid above a pH of about 8. Hence, during oxidation,the pH must be controlled to fall within the range from about 4.5 toabout 8. Most preferably, the pH is maintained to fall within the rangefrom about 5 to about 6.5 since the enzyme action is most efiicient inthis range.

One preferred procedure consists of using calcium carbonate as the baseto control the extent of reaction of enzymatically oxidizing the glucosein greens. The greens are obtained from a dextrose crystallizationprocess, and have a solids content adjusted by dilution if necessaryfalling within the range from about 10% to about by weight. A product isrecovered that is potentially usable as a poultry or cattle feed. In themost preferred procedure,

components for feeds usable for poultry, cattle, etc., are produced fromgreens having a D13. falling within the range from about 70 to about 80.

The product obtained from greens oxidized as described above preferablyhas a dextrose content falling within the range from about 25% to about60%, a maltose co'ntent falling within the range from about to about25%, a calcium gluconate content falling within the range from about 5%to about 25%, and a higher saccharides content falling within the rangefrom about 15% to about 30%, all percent figures being by weight basedon total dry substance, and has a D.E. falling within the range fromabout 40 to about 80.

In another preferred embodiment, calcium carbonate is used as the baseand the glucose in a starch hydrolyzate solution having a falling withinthe range' from about to about 70 is enzymatically oxidized to obtain aproduct which may be used as a baby food, a dietetic food, a clinicalfood, for poultry feeding, for cattle feeding, etc. A starch hydrolyzatewith a DB. falling within the range of from about 25 to about 40 is thepreferred starting material for preparing these novelcarbohydrategluconate products. The preferred product has a dextrosecontent falling within the range from about 0.1% to about 10%, a calciumgluconate content falling within the range from about 10% to about 60%,and a higher saccharides content falling within the range from about 50%to about 80%, all percent figures being by weight based on total drysubstance, and has a dextrose equivalent falling within the range fromabout 1 to about 25. More preferably, an amount of calcium carbonate isadded sutficient to reduce the DE. through enzymatic formation ofcalcium gluconate to a value of no more than 5. Most preferably, thecalcium gluconate content in the final product is about 30% by weight.

The calcium gluconate containing product may be converted into an irongluconate product by passing a solution containing up to about 40%calicum gluconate through a cation exchange column containing ferrous'iron wherein the ferrous ions will leave the column to form ferrousgluconate and the calcium ions will replace the ferrous ions on thecation exchange column. The ferrous gluconate product. is useful as afoam stabilizer in beers and it may also be added to animal feeds toimprove the red color and nutritional value of meat.

In each of the above examples, a powdered product may be obtained byspray drying the reaction product which can then be easily packaged anddistributed. The powder may also be compressed into solid cakes for useas a building material.

In a further preferred embodiment, a carbohydrategluconic acid productusable as a soft drink syrup is prepared by starting with a starchhydrolyzate with a DB. of above about 85. Sufiicient sodium hydroxide isadded progressively to the starch hydrolyzate while maintaining the .pHto fall within the range from about 4.5 to about 8, during enzymolysisto give a gluconic acid content in the product after conversion of thesodium gluconate to gluconic acid, falling within the range from about5% to about 25% by weight of total dry substance. Preferably, the pH iscontrolled so as to fall within the range from about 5 to about 6.5during the sodium hydroxide addition. The preferred product has alevulose content falling within the range from about 10% to about 50%,and a dextrose content falling within the range from about 35% to about70%, all percent figures being by weight based on dry substance. Mostpreferably, the gluconic acid content of the product is about by weight.

The sodium gluconate is converted to gluconic acid by passing theproduct obtained as described above through a cation exchange columnwhich has been saturated with hydrogen ions wherein the sodium ionsleave the solution and are absorbed on the column and the hydrogen ionsleave the column and enter the solution. Alternatively, the sodium ionsmay be replaced by hydrogen ions, by electrodialysis, or other chemicaltechniques.

The treated hydrolyzate may be concentrated for use as a soft drinksyrup by removal of water by evaporation, distillation, freezing orother method or used, for this and other purposes, withoutconcentrating. Additional sweetening agents, flavors, preservatives,etc. may be added to the hydrolyzate or concentrated syrup to adjustflavor and improve storability. The additional sweetening agents arepreferably sweet dextrose solids, for example a mixture with a levulosecontent falling within the range from about 24% to about 29%, a dextrosecontent falling within the range from about 1% to about 3%, and theremainder higher saccharides, all percent figures being by weight basedon dry substance. The additional sweetening agents, fiavors andpreservatives may alternatively be mixed with a soft drink made from thehydrolyzate or concentrated syrup.

Preferably, the gluconic acid content of the soft drink should fall inthe range from about 0.8% to about 0.16% by weight. Most preferably, thesoft drink is carbonated by pressurization and equilibration with carbondioxide gas. The tart flavor of the soft drink is due to the gluconicacid content. Taste tests of the soft drink formulated in this mannerand which contained orange and lemon flavoring materials have been veryencouraging.

The following examples illustrate processes for preparing the novelcarbohydrate gluconate products of this invention. All percentagefigures are weight percent based on dry substance unless otherwisedefined.

Example l.Preparation of calcium gluconate product from greens Thisexample demonstrates the preparation of high calcium product suitablefor use as a constituent of a poultry feed, a cattle feed, etc., -orwhich may be packed together to form building blocks, etc.

Greens, obtained from a dextrose crystallization process and consistingof 57% dextrose, 15% maltose-isomaltose and 27% higher saccharides (1%analytical uncertainty) with a composite DB. of 76, were diluted to a40% (40 grams per ml.) solution with water. The glucose oxidase enzymeOvazyme, obtained from Fermco Laboratories, Chicago, 111., Was added ina concentration of 0.01%. Suificient calcium carbonate was added to themixture to produce 15 calcium gluconate in the final prodduct, theentire reaction mass was constantly agitated, in a sealed vessel at 35C., and oxygen gas was supplied to maintain the reaction vessel at about1 p.s.i.g. positive pressure. The reaction ceased when sufficientcalcium carbonate had been transformed, through neutralizing thegluconic acid formed, into calcium gluconate so that the pH of thesolution had dropped far enough to stop enzyme action. The analysis ofthe resulting syrup showed 42% dextrose, 15% maltose-isomaltose, 15%gluconate, and 27% higher saccharides (1% analytical uncertainty). Thesyrup had a D.E. of 61. The product was easily spray dried.

Example 2.--Preparation of gluconic acid product from high D.S. starchhydrolyzate A starch hydrolyzate was coverted to a dextrose-levulosesolution which exhibited a D.E. of 96.8, the solids therein consistingof 66.4% dextrose, and 27.5% levulose and the remainder highersaccharides, by standard techniques well known in the art. The solutionwas placed in a closed reaction vessel with glucose oxidase enzyme.Sufficient sodium hydroxide was added dropwise to the reaction vesselduring the course of the reaction to transform 15 of the dextrose intosodium gluconate, based on total sodium hydroxide added. The pH wasmaintained in the range of 5 to 6.5 during NaOH addition. Oxygen wasadded to the reaction vessel and a positive pressure of about 1 p.s.i.g.was maintained. When all of the sodium hydroxide had been consumed, thereaction ceased due to inactivation of the enzyme as the pH dropped. Theresulting solution was treated by electrodialysis to convert the sodiumgulconate into gluconic acid. An acid sweet syrup was obtained having acomposition of the solids therein of 51% dextrose, 27.5% levulose, 15%gluconic acid, and the remainder higher saccharides. The sweeteningpower of this syrup was 90% of that of sucrose.

This example demonstrates the preparation of an acid sweet syrup, theacidity of which is due to the presence of gluonic acid.

Example 3.Preparation of calcium gluconate product from starchhydrolyzate An alpha amylase treated hydrolyzate consisting of 32%dextrose and 68% saccharides which exhibited a DB of 45, was put in aclosed reaction vessel with glucose oxidase enzyme and with suflicientcalcium carbonate to convert 30% of the 32% of the dextrose into calciumgluconate. The reaction was allowed to continue for seven hours. Theproduct obtained showed an analysis of 2% dextrose, 30% calciumgluconate and 68% higher saccharides. It exhibited at DB. of 13.

The production of high calcium products potentially usable as babyfoods, dietetic foods, clinical foods, poultry feed, cattle feeds,baking additives, etc., is described in this example.

Example 4.-Preparation and testing of lemon flavored soft drinks A sweetsyrup solution was prepared consisting of dextrose-67%, levulose26%,maltose-1.2%, maltotriose1.3% and higher saccharides-4.2%, (weightpercent of total solids, remainder uncertain due to analytical error).It had a dextrose equivalent of 95 and a pH of 4.5. Six blends were thenmade up using the gluconic acid containing syrup of Example 2 and theabove sweet syrup in different proportions. A seventh blend was made upto contain 0.17% citric acid and 11% sucrose (percent figures based ontotal weight of solution). Carbonated water was added to each of theblends which was then sealed in a hermetically closed bottle andhomogenized by shaking. The compositions of the soda water resultingfrom diluting each of the seven blended syrups is given in Table 1. Atest panel of eight 8) persons tested each of the seven formulations.Preferences of the members of the panel varied but the majoritypreferred compositions and 6. All test panel members considered thecompositions palatable.

TABLE 1 Calculated formulation, weight percent of ution Component 1 2 34 5 6 7 Citric acid 17 Gluconic acid 32 32 53 8 8 Corn syrup solids- 5.5 10. 9 6.3 7. 4 13 Dextrose. 4. 6 3. 6 7. 3 4.1 4. 8 8. 6 1.8 1.5 2.91.8 2.1 3.6

5 4 7 4 5 8 5. 5 5. 5 4. 5 4. 5 Lemon flavor 15 15 15 .15 l5 15 15 Totalsugars 11 12. 4 11 10. 9 10.8 11.9 13 pH (measured) 2. 4 2. 65 2. 5 2. 52. 3 2. 3 2. 3

The testing of lemon flavored soft drink products prepared by themethods of this invention is described above. The data indicate that thetested compositions exhibit a pleasing flavor.

Example 5.-Preparation and testing of orange flavored soft drinks Agluconic acid-containing syrup conissting of 11.5% gluconic acid, 57.2%dextrose, 23.4% levulose and 7.9% of higher saccharides of a degree ofpolymerization of 2 or higher was prepared by the method of Example 2.The syrup exhibited a dextrose equivalent of 83.5. Blends of thisgluconic acid-containing syrup and the sweet syrup of Example 4 weremade. The blends were then mixed with carbonated water and flavor, andthe resulting soft drinks were tested by a person panel. Equalquantities of orange extract were added to each soft drink. Soft drinksWere made containing the following composition (weight percent ofsolution):

0.2% orange extract was added to each soft drink. All panelists agreethat composition 2 exhibited the most pleasing acidity.

This example demonstrates that pleasant tasting orange flavored softdrinks may also be made by the methods revealed in this disclosure.

Example 6.Preparation and testing of orange fiavored soft drinks todetermine suitable sugar levels A series of seven soft drinks wereprepared all containing 50% based on the weight of solution of gluconicacid. The ratio of sweet dextrose solids from a sweet syrup produced asin Example 4 to sucrose and the total sugar content were varied in theseven soft drinks as shown in Table 2. The sweet dextrose solidsconsisted of 26% levulose, 67% dextrose, 1.2% maltose, and the remainderhigher saccharides. The resulting soft drinks Table (2) were tasted by atest panel of 10 persons. Six of the panelists preferred formulation 5.One preferred formulation 4. One preferred formulation 1 and twopreferred formulation 7. The stability of formulation 5 was tested for 2months at 5 C. and 25 C. and was found to be good.

TABLE 2 Total sugar Weight ratio content, sweet dextrose weight percentsolids/sucrose of solution This example demonstrates that the use ofsweet dextrose solids instead of sucrose in orange flavored soft drinkcompositions imparts improved flavor.

Example 7.Preparation and testing of lemon fiavored soft drinks todetermine suitable sugar levels Four soft drink compositions wereformulated and submitted to a taste test panel. All contained .15 basedon solution weight of lemon extract. The formulations were (weightpercent of solution) The majority of the panel preferred composition 1.

The preference of a test panel for a lemon flavored soft drinkcomposition containing 0.7% gluconic acid and 11% sweet dextrose solidsas compared to a composition containing 0.2% citric acid and 11%sucrose, has been revealed in this example.

The product of Example 1, prepared from greens, showed a significantadvantage over the starting material in that it could be easily spraydried. It may be used as a poultry or cattle feed additive or may bepacked and shaped into blocks and used as a building material.

The product from Example 2 consists of a syrup useable in soft drinks.

The product of Example 3, made from a starch hydrolysate with a DB. of45, due' to its relatively low glucose content, is easy to handle in aspray drying tower. This product should be useful as an additive inpoultry feeds, cattle feeds, in milk replacement substitutes, as aconstituent of dietetic foods, baby foods, desserts, etc.

While the invention has been described in connection with specificembodiments thereof, it will be understood that it is capable of furthermodification and this application is intended to cover any variations,uses, or adaptations of the invention following, in general, theprinciples of the invention and including such departures from thepresent disclosure as come Within known or customary practice in the artto which the invention pertains and as may be applied to the essentialfeatures hereinbefore set forth, and as fall within the scope 'of theinvention.

I claim:

1. A solid free-flowing powered product containing an amount of dextrosefalling within the range from about 25% to about 60%, an amount ofmaltose falling within the range from about 5% to about 25%, an amountof calcium gluconate falling within the range from about 5% to about 25and an amount of higher saccharides falling within the range from about15% to about 30%, and having a dextrose equivalent falling within therange from about to about 80, all percentage figures being by weight.

2. A solid free-flowing powdered product containing an amount ofdextrose falling within the range from about 0.1% to about 10%, anamount of calcium gluconate falling within the range from about 10% toabout and an amount of higher saccharides falling within the range offrom about 50% to about and having a dextrose equivalent falling Withinthe range from about 1 to about 25, all percentage figures being byweight.

References Cited UNITED STATES PATENTS 1,609,064 11/1926 Corbett 99--21,767,178 6/ 1930 Herrick et al. 994 2,087,076 7/1937 Wadsworth et al.99-142 2,567,060 9/1951 Docal 12741 X 3,305,395 2/1967 Scallet et al.127-40 X NORMAN YUDKOFF, Primary Examiner K. VAN WYCK, AssistantExaminer U.S. Cl. X.R.

